Thanks for answering my question.
I forgot to mention that the gauge in the field was calibrated.
I wrote to the manufacturer of the valve. He answered a that "the pressure relief valve is preset only with water. Air is prohibited to adjust valves. The priming and depriming of the loading...
Hi
I am Commissioning Engineer on a Gas Plant Project. A piloted PRV is installed at the discharge of a firewater diesel pump. We tested the PRV (equipped with a pilot) on a certified test bench with air so that the opening pressure was set to 13.7 barg as specified in the PRV's datasheet...